Fluid-actuated shiftable mechanism



Aug. 22, 1961 E. P. BRINKEL FLUID-ACTUATED SHIFTABLE MECHANISM 9 Sheets-Sheet l Filed April 50, 1959 Aug 22, 1961 E. P. BRINKEL 2,997,066

FLUID-ACTUATED SHIFTABLE MECHANISM Filed April 50, 1959 9 Sheets-Sheet 2 Aug- 22, 1961 E. P. BRINKEL 2,997,066

FLUID-ACTUATED SHIFTABLE MECHANISM Filed April 30, 1959 9 Sheets-Sheet 3 /M /f' /ff 5a/f@ fw @W6/f g /f/ /f/ Q/ /if /Q far/ainsi Aug. 22, 1961 E. P. BRINKEL 2,997,066

FLUID-ACTUATED SHIFTABLE MEcHANIsM Filed April 5o, 1959 9 sheets-sheet 4 E. P. BRINKEL 2,997,066

FLUID-ACTUATED SHIFTABLE MECHANISM 9 Sheets-Sheet 5 Aug. 22, 1961 Filed April 50. 1959 Aug. 22, 1961 E. P. BRxNKl-:L 2,997,066

FLUID-ACTUATED SHIFTABLE MECHANISM Filed April 50, 1959 9 sheets-sheet 7 INVENTOR. .Zia/iff 7? Brzv/e Z All@ 22, 1961 E. P. BRINKEL 2,997,066

FLUID-ACTUATED SHIIFTABLE MECHANISM Filed April 30, 1959 l 9 Sheets-Sheet 8 Ill Aug 22 1961 E. P. BRINKEI. 2,997,066

FLUID-ACTUATED SHIFTABLE MECHANISM Filed April 30, 1959 9 Sheets-Sheet 9 razr/M0451 United States Patent 2,997,066 FIJUm-ACTUA'I'ED f-SHIFTABLEMECHAN ISM Edwin P. Brinkel, Royal Oak, Mich.,-a'ssignor to Ross Operating Valve Company,-Detrit, tMich., `a corporation of Michigan s Filed Apr. 30, 1959 Ser. No.r810,034 18 Claims. (Cl. 137-622) This invention relates to valvesfand'inoe'particularly to fluid-actuated shiftable mechanismslfor'achieving alternate shifting of an element between Itwo positions in response to a momentary `signal. This application pertains to a mechanism having the "same 'generalifunction as that disclosed and claimed in copending "application 'Serial No. 691,858 led October 23, 1957 Vby the presentfapplieant and assigned to the assignee of this application, this application having now m a tured into Patent No. 2,921,602 issued January 1`9, V196,01.

It is an object of the present invention 'to provide "a novel and improved Huid-actuated y shifta'ble mechanism which entirely eliminates `the need for vany mechanical `locks or detents, these having been found in many cases Vto require very close tolerances 4and a Vcareful selection of materials.

It is another object 'toprovide an in iprov'ed lmechanism yof this nature which operatesentirely by the use of fluid 'actuated elements, is of relatively inexpensive 'construction and requires aminimum of maintenance It is a further objectto Aprovide Van improved shiftable mechanism of the above character which is vof versatile construction, may be installed in combination with v its controlled or controlling components, and is extremely reliablein use.

It is another object Ato provide "an improved shiftable 'mechanism of this nature which may b'e arranged in groups to achieve a variety of desired operational sequences.

Other objects, features and advantages of the Lpresent invention will become apparent fromfthe following description taken in conjunction with "the accompanying drawings, in which:

FIGURE 1 is a schematic circuit diagram showing the components of one embodiment of the invention 'using three valve spools;

FIGURE 1A is another lform of this schematic cireit diagram showing suitable valve constructions;

FIGURE 2 is a partially schematic `viewof a system using the invention, showing Athe shiftable mechanism housing and covers in elevation;

FIGURE 3 is a fragmentary end fiel'evational view of the housing taken in the direction yof the arrow 23of `FIG URE 2 and showing the locations oftlje'v'alve'spool L'and 'check valve bores;

`FIGURE 4 is van elevational view of 'the gasket adjacent the housing surface shown in FIGURE "3;

FIGURE 5 is a fragmentary V eI`eV'ati'onal"view taken in the direction of the arrow S of VFIGURE 2 and "showing the `surface of the housing opposite that 'sho'wn in -FIG- URE 3;

FIGURE 6 is an "elevational view of the gasket -adjacent the surface shown in FIGURE 5.;

FIGURE 7 iis 'a top plan view of 'the top `gasket taken in the direction of 'the Varrow 7 of VFIGUREZ and showing the pressure and Signal connections;

FIGURE 8 is a top plan view of the bottom ga'sliet Itaken in the direction of the arrow 7 of FIGURE 2 and showing the workin'g'port;

FIGURES r9, 1o land 11 arecrosssetional views taken along the lines Y924-9, 1`0"-'1 0' 'and f11'-"11,`res`pectivly, 'of FIGURE 2 and "showing the various 'mechanism "coffiponents in a starting position, pressurized vportions of the mechanism being indicated by dots;

Hennes 1 2, v13 rand 14 are views sinuiar'ftppio- "URES-Q, -10 and -1'1,'r`espectively, `showing the'parts a second position after-initial application of 'pr'essu'reto the signalconnection;

FIGURES l5, 16 and 17 are viewsshowing'tlieipars after pressure has Vbeen removed froin the :signal Tcorivnection;

FIGURES-18, 19 and 20re views showing theipats `after reapplication of signal pressure;

FIGURE 2l is a schematic circuit diagram showing'itle components of another embodiment iof tlie invention vwhich utilizes tour valve spools;

FIGURE v21A is another `form of the vschefriatic Fifrvvcuit diagramof FIGURE 21,*'sl1owingsuitable valve -'constructions;

'FIGURE 221s a'partauy fschemtifvivv '6ta systf utilizing the embodiment of FIGURE 21 andishownfgtlie shaftable mechanism housing and covers in elevation;

FIGURE 23 is Va fragmentary end elevationalvietv of the housing Ataken in the direction Yof the arrow *of FIGURE 22 and sho-wing the locations dof "the `y'valve spools; Y

FIGURE 24 is an elevational v'view ofthe gasket iadjacent the opposite end of the housing, taken in the direction of the arrow 24 of FIGURE 22;

FIGURE 25 is a top plan view of the top housing vke't taken in the direction of the arrow 25 of'FIGUR `FIGURE 26is a top'plan view Of 111i? bottom gasket taken inthe'same direction as FIGURE 25; FIGURES 27, 28 and 29 are crossgsectional VewstaKen along the lines 27-27, '2S- 28 and 29-'29, respectively, 4of FIGURE 22 and showing the various mechanism components in 'a starting position, pressurized portions of lthe mechanism being indicated by dots;

FIGURES v30, 31 and 32 are views similar to FIGURES 27, 28 and 29, respectively, showing the parts in a `se@ ond position after initial application of pressure to the signal connection;

FIGURES 33, 34 and 35 -are views showing the parts after pressure has been removed from the signal "connection; and

FIGURES 36, 37 and 38 are `views showing the parts after reapplication of signal pressure.

In general terms, the illustrated embodiments of the invention each comprises a housing having a plurality of valve spools and other components such as vcheck valves, the assembly being connectable tol v a. source offmomenl tary uid pressure such as a pilot valve. The pilot could be actuated in any manner such as manually, yby means of a solenoid, or by cam actuation. The novel mechanism is adapted to respondto each momentary'apQ- plication and release of pressure in order to shift a actuated motor between two positions. Upon the first application of pressure from the pilot valve the fluid 'motor would shift from a first to a seco-nd position, and 4would stay in this position after the pilot valve pressure waereleased. Upon the second application vofpilot, valvepressure to themechanism, the fluid motonwould be caused to l'shift back to its rst position. The fluid motor cold control any desired mechanism such as, for eX'ample, diverting gate in a conveyor system or the main valve of a fluidsystem In the shiftable mechanism described in the aforementioned copending application, a control spool was provided which shifted in response to the momentaryfap plication and lwithdrawal of pressure from the pilot valve. An actuating spool was also provided, this spool vshifting once each time the control spool moved in one direction 'and maintaining its position when the V control spool returned. The actuating 'spool controlled the supply and eirhast to the uid motor, "and a mechanical deten't 5r lock connected the control spool and the actuating spool.

According to the present invention, the mechanical detent is entirely eliminated, and the actuating spool is controlled by several other valve spools, the connections between the spools being such that a foolproof and ecient actuating spool shift is effected.

Referring to the embodiment of the invention shown in FIGURES 1-20, FIGURE 1 (which uses symbols adopted by the Joint Industry Conference) shows a mechanism generally indicated at 101 having a three-way valve spool 102 with a supply port 103, a working port 104 and an exhaust port 105. As is seen best in FIGURE 2, port 104 is adapted to be connected to a fluid motor 110,

whereby pressurizing of port 104 will move the motor in 'to exhaust port 105.

A signal port 106 is also connected to unit 101 andis `adapted to be controlled by a pilot valve 107. seen in FIGURE 2. This pilot valve may be operated by any appropriate means such as a solenoid 108 momentarily Venergizable by a push button switch 109. For illustrative purposes, it may be assumed that when solenoid 108 Vis in its deenergized position, port 106 will be connected to an exhaust port 111, while energization of solenoid 108 Vwill cause valve 107 to shift so as to connect port 106 with a fluid pressureV supply port 112. It should be noted that although the schematicshowing in FIGURE 2 illus :trates a pilot valve 107 and motor .110 as being separated from unit 101, one or both of components 106 and :107 could be combined with unit 101 in a unitary structure such as a sandwich construction. p

' Unit 101 comprises a disk-shaped block or housing A113 having at surfaces 114 and 115 at opposite sides thereof, and additional flat surfaces 116 and 117 at opposite sides of the peripheral disk wall. Four bores 118, '119, 121 and 122 are provided in housing 113, these bores extending between surfaces 116 and `117. Bore 118 carries a valve spool 123 and has a port 124 at a central portion thereof which is connected with exhaust port 105. A spring 125 urges spool 123 toward surface 117 of the housing,v the spool forming a chamber 126 at 'this end of bore 118. Cover plates 127 and 128 are se- 'cured to surfaces 116 and 117, respectively, with gaskets l129 and 131 being disposed between the cover plates and their corresponding surfaces.A As seen in FIGURE 6, Ugasket 131 has a diagonal passage 132 connecting chamber 126 with the corresponding end of bore 122. A chamber 133 is formed at the opposite end of valve spool 123. When spool 123 is in its right-hand position as shown in FIGURES 9, 12 and l5, a seal 134 will separate chamber 133 from exhaust port 124, but when the valve spool is shifted to its left-hand position as seen in FIGURE 18, chamber 133 will be connected to ex- 'this passage tending to lift the check valve off its seat.

When valve spool 135 is in its left-hand position as seen in FIGURES 9 and 12, signal port 106 will be connected with chamber 138. A piston area 141 and a spring 142 urge spool 135 to its left-hand position.

A chamber 143 is provided at the right-hand end of bore 119 and is connected to signal port 106 when spool A135 is in its right-hand position as seen in FIGURES -15 Vwith exhaust chamber 155.

4 and 18. Chamber 143 is connected to a chamber 144 at the left-hand end of bore 119 by an axial passage 145 within spool 135. Chamber 144 provides a piston area urging spool to the right. Cover plates 146 and 147 are provided for surfaces 114 and 115, respectively, of housing 113, gaskets 148 and 149 being provided between these cover plates and their corresponding surfaces. As seen in FIGURE 7, gasket 148 has a passage 150 which connects chamber 143 with chamber 126. A piston area 151 is also provided on spool 135 in opposition to piston area 141, this piston area being connected by a restricted opening 152 to the side of check valve 136 opposite that connected to passage 139. v

Bore 121 carries valve spool 102 and working port 104 is connected to the central portion of this bore and extends to the underside of unit 101. Supply port 103 is 'port 104 through a restricted passageway 158 and a passage 159 formed in gasket.149, as seen in FIGURE 8. 'When spool102 is in its left-hand position as seenin FIGURES l1 and 20, working port 104 will be connected As previously described, the right-.hand end of bore 122 is connected to chamber 126 by means of passage 132 in gasket 131. j

As seen in FIGURE 4', gasket 129 is provided with a triangular opening 164 which serves to connect bore 137 with bores 118 and 121. This serves in eifect to connect 'working port 104, through gasket passage 159, restriction 158 and chamber 157, with chamber 133 of bore 118 and to the exit side of check valve 136. lt will be noted that ditfe'zren'tial area 151 of valve spool 135 is `also connected to this side of the check valve through restriction 152. Gasket 131 is further provided with an opening 165 leading from the chamber in bore 119 which contains spring 142.

- Operation In studying the operation of unit 101, reference may be made to the schematic diagrams of FIGURES l and 1A as well as the sequential showings of FIGURES 9-20 which show the valve spools in their different positions. FIGURES l and 1A show the unit with the valve spools in their assumed starting positions, which are the same as the positions in the fourth step of the sequence of operations. FIGURES 9-11 also show the parts in this condition, whereas each of the next three groups of figures show the parts in their first, second, and third positions, respectively.

Assuming starting conditions in which pilot valve 107 in FIGURE 2 is Vconnected to exhaust, with solenoid 108 deenergized, signal port 106 will be connected to exhaust as will working port 104. It may thus he assumed that fluid motor 110 is in its upper position in FIG- URE 2.

When push button 109 is depressed, solenoid 108 will be energized to move pilot valve 107 to its supply position. This will cause signal port 106 to be pressurized,

the pressure flowing through chamber 138 of bore 119.

passage 139, check valve 136, bore 137 and passage 164 to chamber157of bore 121. The pressure in chamber 138 will cause pistonarea;A 141 to be pressurized, while tica-25085 .tto lbe pressurized, las seen in-LFIGURE 14. Piston area iwardly inFIGURE 1A. This will cause working port 104 lto `-be connected "to fsupply port 103, rnoving motor y1.10 '-downwardly. Piston area 151of valve spool 135 "will also be pressurized through restriction 152 which `leads Ifrom check valve bore 137, `thepressureon this pist'onarea balancing lth'e pressure 'on l'piston area 141. However, valve'fspool 135 will not 'shift at this vtime due tothe-presence of spring 142. The presence of restric- 't'on 152 -will insure vthat 'piston a'rea 151 vis not .presi's'rized before piston Varea 141, sothat there will be no danger ofvalve spool135ishiftin'g totherightin FIGURE 1 (upwardly in FIGURE 1A) at this time.

Upon release of ipush button 109 solenoid 1.08 will be deenergizedcausingLpilot valve 107 to shift toy its exhaust pbsitio'n. As signal pont 106 nis connected lto exhaust,

`piston area 141 will likewise be depressurized, vand the Sp'ressure onpisto'n area 151 will overcome 'spring 142 and cause valve-"spool i135 to Vshift'to the fright 'as shownin FIGURE (upwardlyin- FIGURE-1). Itwill be noted ithat, since the pressure in chamber 157 as well as the -pressure exerted on piston 'area 15-1`is trapped by .check valve 136, Vthe exhaustion of lsignal v'port 106 will not iaffect the position of Valve spool 102, so that working lport 104 willstill remain connected "to supply port |103. Furthermore, work-ing point 104 will be connected Vwith -fcliamber 157 through gasket passage 159-and restriction `158, so that -any leakage pastcheck valve 136 will bereiplenish'ed, 'thus linsuring th'e maintenance of valve 'spools "-102 and 135 in -the'p'o'sitions 'of FIGURES V17 and 15, yretspectively. v N

lWhen pushbutton 109 is again depressed, signal "106 'will be pressurized, V"and with'valve spool y135 'fin the position of FIGURE l5, (the upperzpositio-n inFIGURE 1A), 'pressure will be conducted through chamber 143 A4'andp'assage 145-to Achamber 144, as shown in FIGURE A1"8-(at:the bottom of bore 119 in FIGURE 1A). Sinoe ychamber 143 is connected to chamber v126 (at the top of bore 118 in FIGURE 1A) -by gasket passage 150, -this "chamber willbepressurized, overcoming-spring 125 and the pressure in chamber V133, and shifting valvespool l123 `tothe left as shown in FIGURE 18 Atar-downwardly as "sho'wn in FIGURE lA. This will connect vchamber 133 with port 124 which in turn is connected to exhaust port 105 through chamber 155. Since chamber 133 is connected to chamber 157 through-gasket passage 164, pistou Tarea 156 will also Ibe exhausted. Thus, piston area 154, which isV connected to supply port103, will cause valve ^spool 102 to be shifted to the left `as Shown in FIGURE 20 (downwardly Vin FIGURE lA). This in turn vwill serve 4to connect working port 104 with exhaust port 105. uPiston area 151 of valve spool 135, which is 'connected )toohamber 133 through restriction 152, check valve bore i137 Tand gasket passage 164, will also be connected to exhaust, but lsince pressure is applied to chamber 144, Valve spool 135 will remain in its right-hand position "(upper position in FIGURE lA).

lWhen `push button 109' is .again released, signal port 106 will be connected to exhaust. This will exhaust chamber 126 of bore 118 through gasket 'passage -13'2 and check valve 161. Valve spool 123 will thus be shifted to its righthand position as seen in FIGURE 9 (upper l'position in FIGURE 1A) by spring 125. 'Char'nlber 144' will likewise be connected to exhaust through passage 145 in valve spool 135, chamber 143 and port 106. This 'will causevalve spool 135 to shift to the left (downwardly in FIGURE 1A) due to spring 142. Any remaining .pressure trapped in chamber w144 after spool 135 has 3shifted will be `permitted to escape through passage 145, chamber 143, gasket passage 1501, `charnlber 126, .lgasket passage 132, and check valve 161 to signal port 106. This pressure `relief vmeans would be especially imspool 123` to shift to -its exhaust position. `of checkvalve 136 between control spool 135 and'piston port Vis exhausted -for the second time. Vacting on control spool 135 areso arranged that when lpcifrtant where `incompressible =lluid I is -4bei-ng used. Valve #102 `will-vremain initsv exhaust position duei'totheipressure on piston area 154. The parts will'thus lbein'their posi- 'tionsshown `in FIGURES y1A, 9, 910 `and ll and A-w'ill be ready for a repetition of the cycle described above.

.In view of this description `of the operation, the vgeneral functions of the variousv'alve spools-could be generally-stated as follows: Valve spool 102 could betermed an actuating spool, since it directly controls the connection of -uid motor 110 Vto supply or exhaust. Valve spool 123 may be identified as an exhaust spoolin that it is movable between a closed ,position (FIGURES f9, l-2

and `15) andv an'exhaust position (FIGURE 18) in which it causes actuating spool 102 to be `shifted to its exhaust position. Valve spool 135 'cauld be terme'da control spool in that it is shiftable Jbetween a rstposition (FIG- URES `9 and-l2) in which application of 'signalpressure will cause the actuating spool t'ofshift `to i-ts supply-position, and a second position (FIGURES 15 and 18) 1in which 'application of signal .pressure will cause exhaust The .position area 156 of actuating spool 102 serves to maintain the actuating spool in its supply position"when signal port 106 isrst connected to exhaust after being pressurized. At the same time, the first exhaustion of signal vport 106 causes the control spool to shift toits right-hand. position (upper position in FIGURE 1A) because of .pressure on piston Varea151 trapped by check valve 136. This Shifting enables actuation of exhaust 'spool-123 when the-signal port is next pressurized. Shifting of the control 'spool also cuts oi the connection between signal port 106 and check valve 136. When exhaust'valvef123 shifts/.to

-its left-hand position (lower position in'FIGURE 1A) upon the second pressurizing of signal port `106, not only will actuating valve `102 be caused to shift to itsexhau'st position, but piston area 151 will be depressurized, readying control spool 135 4for leftward shifting (downwardly The presence of check valve spool will return to its closed position when the signal The .piston areas the rsignal port is depressurized for the second time 'the 'control -spool will be returned to its first yposition by spring `142 in readiness for another cycle.

It should be'observed that the illustrated embodiment of the invention could be varied in several ways within the principles of the-invention. For example, springs 125 and 142 could be replaced by iluidipressure, and piston `area .154 could 1be replaced by Va spring. The unit could sence, this embodiment differs from the previous one in A209 and a right-hand gasket 21-1.

that a fourth valve spool is included which perfor-ms some of the functions of the differential areas on control spool 135, the control spool in the present embodiment being of correspondingly simpler construction.

Referring to FIGURE 22, the shiftable mechanism is generally indicated at 201 and comprises a. at cylindrical housing 202 with a top cover 203, a top gasket 204, a bottom cover 205, a bottom gasket 206, a-left-hand erid 'cover 20'7, a left-hand gasket 208, a right-hand end cover Mechanism 201ispro- 'vided with a pressure supply port 212 extending through cover 203 and gasket 204, a signal port 213, a working port 214 connected to a motor 215, and an exhaust port 217. Port 213 extends through top cover 203 while port 214 extends through bottom cover 205 and exhaust port 217 extends from the side of the housing. Signal .port 213 is connected to a three-way valve 218 having a `supconstant pressure from supply port 212. passes through a passage 242 in gasket 204, a passage ply port 219 and an exhaust port 221 and being controlled by means such as momentarily actuatable solenoid 222 controlled by a push button 223.

As seen in FIGURE 23, housing 202 is provided with bores 224, 225, 226 and 227, as well as a centralbore 228. Bore 224 carries an exhaust spool 29 and bore 225 carries a control spool 231, while bore 226 carries an actuating spool 232 and bore 227 carries an auxiliary control spool 233.

Actuating spool 232 `is similar in construction to spool 102 of the previous embodiment in that it is movable between a left-hand position in FIGURE 21 (lower position in FIGURE 21A) in which working port 214 is conlnected to exhaust port 217, and a right-hand position (upper position in FIGURE 21A) in which supply port 212 is connected to working port 214. Control spool 231 is movable between a left-hand vposition as shown in FIGURE 21 (lower position in FIGURE 21A) in which signal port 213 is connected to the entrance o-f a check valve 234, and a right-hand position (upper position in FIGURE 21A) in which the signal port is connected to a chamber 235 at the right-hand end of bore 224. Exhaust spool 229 is shiftable between a right-hand position as shown in FIGURE 21 (upper position in FIGURE 21A) in which the valve is closed and a left-hand position (lower position in FIGURE 21A) in which the exit of check valve 234 is connected to exhaust. Auxiliary control spool 233 is movable between `a left-hand position yas shown in FIGURE 21 (lower position in FIGURE 21A) in which working port 214 is connected -to a chamber 236 at the left-hand end of bore 225, (lower end in FIGURE 21A), and a right-hand position (upper position in FIGURE 21A) in which this connection is cut on?. Spool 233 yis shifted from its left-hand to its right-hand 'position from its lower to its upper position in FIGURE 21A) each time signal port 213 is pressurized, this signal pressure being conducted to a chamber 237 at the lefthand end of bore 227.

`The remaining constructional features of mechanism 201 may perhaps best be understood by a description of the operational sequence of the mechanism, reference being made particularly to FIGURES 21A and 27-38. Assuming an initial condition in which signal port 213 is -connected to exhaust and working port 214 is likewise exhausted, application of pressure to signal port 213 will cause the parts to be shifted from Itheir positions shown in FIGURES 21A and 27-29 to the positions shown in FIG- URES 30-32. More specically, port 213 extends through housing 202, passing through bore 225 and into a chamber 238 of bore 227. Chamber 238 leads to a passage 239 in spool 233, this passage leading to chamber 237, `and spool 233 will thus move -to the right (upwardly in FIGURE 21A) with the aid of a spring 240 in chamber 237. This movement will be against the pressure exerted on 'the right-hand end of spool 233 (upper end in FIGURE 21A) by fluid in ya chamber 241 which is under This pressure 242 which connects passage 242 with a chamber 243 in the right-hand end of bore 226 (upper end in FIGURE 21A), 'and ya passage 244 in gasket 211 which connects chambers 243 and 241. Passage 242 also passes through Ia chamber 258 in bore 224 and maintains this chamber under constant pressure, for purposes described below.

The pressure at signal port 213 will also pass through bore 225 for valve spool 231, from where it will ow l.through la passage 245 to check valve 234, and from bore 228 through a passage 246 to the left-hand chamber 247 (lower chamber in FIGURE 21A) of actuating spool 232.

This will cause valve spool 232 -to shift to its right-hand position yas seen in FIGURE 32 (upper position in FIG- URE 21A), connecting working port 214 to constantly pressurized chamber 243. Motor 215 will thus be actuated. Pressure will lalso ow through a restricted passage '248,aligned with passage 246 las seen in the figures, to a triangular passage 249 formed in gasket 206. Passage 249 connects restriction 248 with working port 214. This connection will insure the continued application of pressure to chamber 247 from chamber 243 even after the signal pressure has been removed. The shifting of spool 232 and pressurization of Working port 214 (which is connected to bore 227 by gasket passage 249) serves to ready valve spool 233 for shifting spool 231 in the next step of the cyole, as described below. For the time being, however, this pressure has no eifect since spool 233 is in its closed position. The presence of flow resistance (represented by a restriction 250 in FIGURES 21 and 21A) in the path leading from signal port 213 to chamber 247 insures that valve spool 233 will shift to its closed position before pressure is built up in the central portion of bore 227.

. Upon deenergization of solenoid 221, signal port 213 will be connected to exhaust. Due to check valve 234, chamber 247 of bore 226 'as well as the central portion -of bore 227 will remain pressurized, this pressure being supplied from chamber 243 to triangular passage 249. Chambers 237 and 238 will be evacuated, and the pressure in chamber 241 will cause spool 233 to shift to the left las shown in FIGURE 35 (downwardly in FIGURE 21A). This will cause pressurizing of a passage 251 leading from a chamber 252 in bore 227 to chamber 236 in the left-hand portion of bore 225 (lower portion in FIG- URE 21A). This will cause valve 231 to shift to the right as shown in FIGURE 33 (upwardly in FIGURE 21A) closing la valve member 253 against the action of a spring 254, thus shutting off signal port 213 from passage 245. This will have no immediate effect, `and working port 214 will remain pressurized. At the same time, signal port 213 will be connected to a chamber 255 at the right-hand end of bore 225 (upper end in FIGURE 21A) this chamber leading to chamber 235 at the right-hand end of exhaust spool 229 (upper end in FIGURE 21A) through a passage 256 in gasket 211. This will place the parts in lreadiness for shifting of exhaust spool 229 to its exhaust position during the next step of the cycle. For the time being, however, spool 229 will be held in its right-hand position (upper position in FIGURE 21A) against the force of a spring 257 by a constantly pressurized differential area in chamber 258 connected to passage 242', and a chamber 259 `at the left-hand end of bore 224 (lower end in FIGURE 21A) which is connected with passage 246.

Upon reapplioation of signal pressure to port 213, valve spool 233 will again be shifted to the right Ias shown in FIGURE 38 (upwardly in FIGURE 21A). Chamber 252, passage 251 and chamber 236 will remain pressurized, thus maintaining valve spool 231 in its right-hand position (upper position in FIGURE 21A). Pressure will ow from port 213 through chamber 255 and passage 256 to chamber 235, thus shifting exhaust spool 229 to its left-hand position as seen in FIGURE 36 (lower position in FIGURE 21A). Chamber 259 `at the left-hand end of bore 224 (lower end in FIGURE 21A) will thus be connected to exhaust port 217 which leads through the central portion of bore 229. Passage 246 and chamber 247 of bore 226 will thus `also be connected to exhaust, and the constant pressure in chamber 243 will cause valve spool 232 to shift to its left-hand position as shown in FIGURE 38 (lower position in FIGURE 21A). Working port 214 will thus be connected to a chamber 260 in bore 226 which leads to exhaust port 217. The presence of restriction 250 will prevent the depressum'zation of chamber 252 before valve spool 233 closes.

Upon the second release of pressure from signal port 213, the pressure in chambers 255 and 235 will be exhausted, and the constant pressure applied to chamber 258 will cause valve spool 229 to be shifted to the right as shown in FIGURE 27 (downwardly in FIGURE 21A) This will close the connection between the chamber 259 and exhaust port 217. Release of pressure from chamber i237 `vvill cause Valve' spool 233 to Abeshitted to'theleft as seen in FIGURE 29 (downwardlyin. FIGUREZlA) "bytthepressure in chamber 241. Chamber-252 will thus be connected with triangular passage. 249 which viniturn :iis` connected to exhaust through bore 226-an'clv chamber fv60. Sincechamber V2.126 of bore 2251is connected 'to "chamber 252 through passage 251,'valvespool 231Will bef-shifted to the left as seen in `FIGURE 27 (downwardly linlFIGURE 21A) by spring 254. Ilniswillreopen the `Vconnection between signal portZS and Icheck'valve 234 "in readiness-for another cycle. The parts will .be in their (original position as shown in-FIGURES21Aand27-29 lwithworking port 214 connectedto exhaust.

yAs in the previous embodimentof' the invention,.'it`will fbe noted that'the parts could be altered, .for 'example "by Lsubstituting fdiiferential x'areas' fori return springs. Y.Actuatvv'ing '-valve'232 could be aseparate unit `.if vdesired, and 'could-also bealteredfsoias to control a double acting fluid .n1`." tor.

`While it will be apparenttliat the "embodiments "of the invention herein `disclosed are -well "calculated Lto .fulfill the `objects ofl the-invention, it .will ibe fappreci-ate'd that vIthe invention is susceptible to'modication, `variation and lchange'without departing .from the 'proper :scope orfair fmeaning ofithe subjoined claims.

v4:What is claimediis:

.1. 'In 1a Vvfluid-actuated fshiftable 'r mechanism, actu- `:atingfmember movable .between first and second positions, :fmeans urgingsaidactuating memberitowarditsirst posittion, iluidpressure responsivelmeansfor overcoming'said VIrst vmeans and moving 1 said member to` its second posiltio'n, vEa signal port, a :control 1valve movable between sa :'rst positionwconnectingandiasecond position :disconnectin'g said signalxport :and said fluidpressure Lresponsive f'mean's, means urgingsaid controlvalve .towardL-its'frst "position, *whereby a first application of pressure to :said signl Sport l'will .cause said factuating member to .shift "to .its second position, f means"responsive to irelease of fsaid Irst 'pressure application for `maintainingthe 'pressurized `condition 'of said Yfluid 4pressure responsive 'means and shift-ing said `control valve toits Asecond position,.means responsive to a second pressure application I-tofsaid signal port 'for "releasing "the pressure on said .fluid pressure vreusponsive means, whereby said :actuating 'member will 're- `turn "to -its irst position, and means'responsive to'relea'se fofrsaid'isecond pressure applicationaforreturningsaidcon trol valve to its rst position.

i2. 4"Inra fiuidactuated shiftablelmechanism, an *actuating valve movable between supply land .exhaustpositions, means `constantly urging said actuating valve toward its rexhaust position, lapiston area'for overcomingsaidliirst @means and'movingsaid yactuating valve tofitssupply posit-ion, a'si'gnal port, -a-control Valve .movablebetwe'en fa first position connecting and a second position disconrnecting said signal port andsaid piston area, means urg- `ing `said control valve toward its first position 'whereby Ya irst `application of pressureto said signal port will cause `'.sa'idfactuating valveto shift to its supply position, means .responsive to release of -said first pressure application .for fmaintainingthe pressurized `condition of said `lpiston area and shifting `said control -valve to its second position, ime'ans responsive to aisecond pressure application to said :signal Aport hfor releasing the fpressu're fon said piston '-are'a, whereby said actuating valve Will return toiits exhaust position, and means `responsive Avto release/of said second pressure :application for vreturning :said contrVvalveto "its first position.

"In va fluid actuated shiftable mechanism, an actuatlin'g' Jmem-ber movable betweenfirst and second'p'ositions, :means constantly urging .said actuating member toward itsfirst position, vvfluid pressure responsive means'for overcoming A'said Ifirst means Vand'mov-ing said 'actuating mem- Vbertoits second position, a signal lport, a control vlv'e 1cn'uiwable `between a l'first position connecting and "a :sec-

fes

7'ond positiondisconn'ecting said signal uport Aand said "tid 75 .1,0 Ypressure Iresponsive means, 'fmeans .urgingsaidcontol lvalveKto/ward' itsrstposition' whereby by Ya .first applica- .tion off pressure toisaid'signal port will 'causesaid actu'- Iatingmember to shift to its second position, a check valve 'for maintaining the pressurized condition of said fluid pressure responsive means upon release of said tirstpr'es- "sure application, means `responsive to said release for shiftingisaidcontrol valve to its second position, .means Aresponsive to aV second pressure application to said signal port forreleasing the pressure on said uid pressure responsive means, whereby said actuating member'willlreturn to itsffirst position, .and means responsive to release of `said .second pressure Aapplication for returning ysaid fc'ontrol valve to itsffirst position.

4. The combination according Vto claim 3, the means for l`shiftingsaid Vcontrol valve to its second position comprising afirst differential 'area connected to Vsaid signal -port when .said control valve is in its rst posi-tion Vand `urging the control valve towardits rst position, asecond differential area :for urging said control valve .toits-.second position, 'and .a-restricted connection between vsaid signal port 'and said 'second differential area when Asaid vcontrol valveis in itsfrst position, said check valvey pre- 'Venting .ow .from said second differential Varea to Lsaid 'sign'alport whenthesignal port is depressurized.

15. .The combination Iaccording to claim 3, further'provid'edwith'an'exhaust Valve movable from a closedpo'siltionfto an exhaustposition connecting said .iluid 'pressure 'responsive .means to exhaust, means urging said exhaust -valvet`oits closed position, and means responsive to .ap- 'plication lof pressure to said signal'port when said control valveisin its second position for .moving said'e'xfhaust valve'to itsexhaust position.

f6. The .combination according to claim 5, themeans for urging said exhaust valve to its exhaust positioncomprising'fa diiferential arca, and a 'check valve connecting 'Ssaid differential area 'to isai'd signal port whereby 'release o'f fsignal port `pressure will '.permitsaid exhaust valve 'to lreturnito' its closedlposition.

7. The "combination according to claim 3, the means Vfor shifting said control valveto its second position com- Iprising Ia .'dirferenti'al area, a connection between saidlfluid pressure responsive means and said differential area when said Vcontrol'valve isin Vits first position, au auxiliary con- 'trol`val've-movable between an open first Vposition and 'a `second position 'closing .said last-'mentioned connection, means urging said auxiliary control valve to its open position, andlmeans responsive `to application of pressure tofsaidsign'al port to move said lauxiliary control valve 'to itsclosed'posit'ion.

8. The 'combination 'according to claim 7, further provided "with a Arestriction in the connection leading to 'said "control valve differential area, whereby said auxiliary 4control valve 'will be moved toits closed position upon a first `application of pressure to said signal port before said-control valve moves 'to its .second'position .9. 'In a uid actuatedshiftable mechanism, .an Iactuating valve having supply, exhaust and working ports and vm'ovlabl'e .between supply and exhaust positions, means vconstantly urging said actuating valve toward .its exhaust position, a differential area for overcoming said first Vmeans and moving said actuating valve -to its supply position, .azsignal port, a control valve movable between 'a .first position connecting and a second position disconnect- Aing said signalport and said differential area, means urging .said "control valve toward its first position whereby a .first application of pressure to said signal port will cause said actuating valve to shift to its supply position, m'eans responsive to vrelease of said first pressure applicationlfor maintaining the pressurized 'condition of said differential area-:and shifting said control valve to its second position, 'ra restricted feedback connection leading from the 'working lport of said actuating valve to said differential 'area for maintaining pressure on said differential area after vsaid signal port Apressure has been released, means respon- "11 'sive to a second pressure application to said signal port for releasing the pressure on said dilerential area, whereby said actuating valve will return toits exhaust position, `and means responsive to release of said second pressure application for returning said control valve to its rst position.

10. In a iluid actuated shiftable mechanism, an actuating member movable between first and second positions, means constantly urging said actuating member toward its second position, a differential area for overcoming said first means and moving said `actuating member to its rst position, a signal port, a control valve movable between a first position connecting and a second position disconnecting said signal port and said differential area, a check .valve in the connection between said control valve and -said differential area permitting ow only to said dilerential area, a rst control valve dilerential area for urging the control valve toward its second position, a restricted connection between the exit side of said check `valve and said rst control valve diierential area, means `actuatable by signal pressure when said control valve is in its second position for releasing pressure from said actuating member and first control valve differential areas, a second diierential area on said control valve for urging the control valve toward its irst position, an unrestricted connection between said second differential area and said signal port when the control valve is in its rst position, means constantly urging said control valve toward its rst `position', and a third differential area connected to said signal port when said control valve is in its second position and adapted to urge said control Valve toward its -second position, whereby said control valve will be held in its second position after pressure has been released ,from said first control valve area by said pressure releasing means.

l1. The combination according to claim 10, said pressure releasing means comprising an exhaust valve, means constantly urging said exhaust valve toward a closed position, a iluid pressure area for urging said exhaust valve -to a second position connecting said actuating member and rst control valve areas to exhaust, an unrestricted 'connection between said signal port and said exhaust valve area when said control valve is in its second position, a second connection extending directly between said exhaust valve area and said signal port, and a check valve in said second connection permitting ow only to said signal port.

l2. In a iluid actuated shiftable mechanism, an actuating spool having a supply port, and exhaust port and a working port and movable between supply and exhaust positions, means constantly urging said actuating spool toward its exhaust position, a lluid pressure area for urging said actuating spool toward its supply position, a signal port, a control spool, means constantly urging said control spool toward a rst position connecting said signal port with said actuating spool iluid pressure area, a check valve in the connection between said control spool and said area permitting flow only to the area from said control spool, a fluid pressure area on said control spool for urging the control spool to a second position shutting ol the connection to said check valve, an exhaust spool, an exhaust connection leading from said actuating spool uid pressure area to said exhaust spool, means constantly urging said exhaust spool toward a closed position, a fluid pressure area on said exhaust spool for urging the exhaust spool to an open position exhausting said actuating spool lluid pressure area, a connection between said signal port and said exhaust spool uid pressure area when said control spool is in its second position, a fluid pressure area on said control spool for urging the control spool to its second` position, a connection between said working port Yand said control spool fluid pressure area, an auxiliary vcontrol spool in said last-mentioned connection, means constantly urging said auxiliary control spool to an open position, and a lluid pressure area on said auxiliary con- -trol-spool Vconnected to said signal port for urging the auxiliary control spool to a closed position.

13. In a uid actuated shiftable mechanism, a signal port, an actuating spool having supply, exhaust and work- Ying ports and movable between a first position connecting 'the exhaust port and a second position connecting the supply port to said working port, means constantly urg- Aby a first application of pressure to said signal port will cause said actuating spool to shift to its second position, 'a check valve in the connection between said control spool and said area for maintaining the pressurized condition of said area after said signal port is depressurized,

an area on said control spool responsive to uid pressure to move the control spool to its second position, a connection between the exit side of said check valve and said .control spool area, rst delay means for causing said control spool area to be ineffective to shift the'control spool to its second position until a first depressurization of said signal port, an exhaust spool movable between "a closed position and a second position connecting the exit side of said check valve to exhaust, means constant- -ly urging said exhaust spool to its closed position, an area on said exhaust spool responsive to fluid pressure to move the exhaust spool to its second position, a connection-be- '.tween said signal port and said exhaust spool area, said -eonnection being open when said control spool is in its second position and closed when the control spool is in its first position, whereby a second application of pressure to said signal port will cause said actuating spool to move to its iirst position and will depressurize said control spool area, and second delay means for causing said control spool urging means to be inelective to return the control spool to its rst position until a second depressurization of said signal port.

14. 'Ihe combination according to claim 13, said first delay means comprising a second area on said control `spool responsive to fluid pressure for urging the control spool to its iirst position, an unrestricted connection between the entrance side of said check valve and said second control spool area, and a restriction in the connection between the exit side of said check valve and the rst control spool area.

l5. The combination according to claim 14, said second delay means comprising a third control spool area connected to said exhaust spool area and responsive to fluid pressure to urge the control spool to its second position.

16. The combination according to claim 13, said rst and second delay means comprising a connection between said working port and said control spool area, an auxiliary control valve in said last-mentioned connection, means urging said auxiliary control valve to an open position, and means responsive to signal port pressure for moving the auxiliary control valve to a closed position.

17. The combination according to claim 13, further provided with a restricted feedback connection between said working port and said actuating spool area.

Y 18. In a uid actuated shiftable mechanism, a housing, supply,exhaust, signal and working ports in said housing, rst, second and third bores within said housing, an actuating spool within said first bore and movable between a first position connecting said exhaust port and a second position connecting said supply port to said working port, means constantly urging said actuating spool toward its yiirst position, an area on said actuating spool responmovable between a first position opening said connection and a second position closing said connection, means urging said control spool to its rst position whereby a irst application of pressure to said signal port will cause said actuating spool to shift to its second position, a check valve within said housing in the connection between said control spool and area for maintaining the pressurized condition of said area after said signal port is depres` surized, an area on said control spool responsive to fluid pressure to move the control spool t-o its second position7 a restricted connection between the exit side of said check valve and said control spool area, a second area on said control spool responsive to duid pressure for urging the control spool to its rst position, an unrestricted connection between the entrance side of said check valve and said second `area, whereby the control spool Will be shifted to its second position upon said first signal port pressure release, an exhaust spool in said third bore movable between a closed position and a second position connecting the exit side of said check valve to exhaust, means constantly urging said exhaust spool to its closed position, an

area on said exhaust spool responsive to fluid pressure to move the exhaust spool to its second position, a connection between said signal port and said exhaust spool area, said connection being open when said control spool is in its second position and closed when the exhaust spool is in its first position, whereby a second application of pressure to said signal port will cause said actuating spool to move to its rst position and will depressurize said first control spool area, and a third control spool area connected to said exhaust spool area and responsive to uid pressure to urge the control spool to its second position, whereby said control spool will be maintained in its second position until the second depressurization of said signal port.

References Cited in the tile of this patent UNITED STATES PATENTS 2,382,224 Hicks Aug. 14, 1945 2,688,314 Holm et al. Sept. 7, 1954 2,854,956 Hager Oct. 7, 1958 2,900,960 Gratzmuller Aug. 25, 1959 

